The automated design issues of modular spindle heads for multi-operational metalcutting machines are considered.An option for expanding technological capabilities through the use of forming units with vertical and horizontal arrangement in the space of the machine working area is given.A 3D project for the drive of the machine's main movement with a built-in horizontal spindle head and replaceable vertical and slotting spindle heads has been developed.In the process of modelling complex drive housing parts and replaceable heads, Creo Parametric CAD functionality was developed.These functionalities with the procedure for interconnecting the three-dimensional design model and the manufactured casting mold are associated.The implementation of this procedure using the example of creating a structural element -a "Casting draft angle" in the housing part manufacturing of a slotting head is presented.The "Mechanism Design" module of the Creo Parametric CAD system models the rack-and-pinion transmission as the translationally moving link intended for processing grooves, blind-shaped surfaces, and internal cavities is used.Ways to improve the design of the rack-and-pinion gear are outlined.The main innovative idea of the rack tooth profile in the form of an arched shape is presentation.Primary analytical dependencies for a complex geometric-kinematic analysis of a rack-and-pinion transmission with arched teeth were obtained.The relationship between transmission parameters and the maximum size of the gear-cutting head has been established.A condition to guarantee the absence of secondary cutting using a gear-cutting head has been introduced.The value of the coefficient KL = 1.13 as an indicator of a decrease in bending stress and, as a consequence, an increase in the load capacity of arched teeth in comparison with straight rack and pinion teeth, all other things being equal is determined.
A virtual debugging and monitoring platform for industrial robots was designed based on digital twin technology to address the high cost and difficulty in maintaining and upgrading the industrial robot system platform in industrial robot experimental teaching.A digital twin model of a real industrial robot system platform was constructed using NX MCD software.Using PLCSIM Advanced high-performance simulator, virtual joint debugging of the entire industrial robot system platform achieved.With the help of OPC communication technology, the virtual platform established data interaction with the real PLC, achieving 3D visual monitoring of the real platform.The effectiveness of using digital twin technology to build a virtual platform was verified by comparing the synchronization accuracy with real robots.The application of this virtual platform effectively saves the on-site debugging cost of equipment, improves the efficiency, autonomy, and safety of experimental teaching, and enhances the visualization, intelligence, and digitalization level of experimental management.
In a wide range of current changes, it is difficult for current transformer to carry out steady energy extraction, because the excitation characteristics of current transformer are interfered by load impedance.To solve this problem, a dynamic impedance control strategy of voltage source converter is proposed.The method dynamically and continuously adjusts the secondary impedance according to the different states of the primary current, which not only meets the requirement of load power consumption under the condition of low current, but also reduces the influence of the magnetic saturation problem of the core.The principle of energy collection is analyzed, and the equivalent model of current transformer and circuit is established.The relationship between excitation characteristics and impedance parameters is discussed empirically-, which lays a foundation for the construction of the final control strategy.The experimental results show that, first, without capacitive impedance control, the effective value of ct induced voltage is 37.313V, and the corresponding energy collection power is 1.39W.Under the capacitive impedance control, the RMS value of ct induced voltage increases to 72.868V and the energy collection power reaches 5.31W.It can be seen that when the capacitive reactance state is changed, the RMS value of induced voltage and energy collection power are significantly different.Second, the output current of the strong current generator is adjusted to 70a, and when the current increases, the system enters the magnetic saturation state.At this time, the positive and negative half waves of the voltage and current on the CT secondary side produce high amplitude spike pulse waves, which is very dangerous to the insulation of the CT winding and the safety of the load equipment.Under the same conditions, after the induction impedance control is added to the CT core, the magnetic saturation state is relieved, and the waveform changes from peak wave to sine wave, the energy taking system returns to normal working state, the DC voltage output is normal, and the system power supply is stable.Third, the output current of the strong current generator continues to increase to 80a, with the increase of the primary current, the system waveform state remains stable, and the induced voltage and DC output voltage remain constant near the preset reference value.It can be concluded that the magnetic induction intensity of the core will be positively affected by the capacitive impedance operation, and the energy supply effect of the transformer will be increased.The operating characteristics of inductance impedance can reduce the magnetic induction intensity of the iron core, thus inhibiting the saturation of the iron core under high current operating conditions and maintaining stable power output.
Nowadays, in spite of advanced technology, there are still some sound problems on modern cars because of mechanical parts, oil lubrications, and electric motors.Due to these unwanted problems, it is necessary to design intelligent predictors such as artificial neural networks.In this investigation, a procedure of testing and evaluation on the sound quality of two types of cars are proposed and sound quality is analyzed through the cars road running test on the providing ground, which is carried out with varying running speed.To improve and predict the results of experimental approach analysis, a proposed neural network predictor is also designed to model of the system for possible experimental applications.The proposed neural network is a feedforward type network, which consists of multi hidden layers.Three different training algorithms are used for training the network.As basic factors for sound quality, only objective factors a considered such as loudness, sharpness, speech intelligibility, sound pressure level.The correlation between sound pressure level and other factors are discussed from a point of view of running speed dependency.Results of both computer simulations and experiments show that the neural predictor algorithm gives good results at accommodating different cases and provides superior prediction on two cars's sound analysis.
Autonomous vehicles must maintain awareness of their surroundings, encompassing other vehicles, pedestrians, traffic signs, and varying road conditions.Among numerous objectives, the most crucial one is the detection of vehicles and pedestrians.Despite advancements, complex traffic scenarios still pose challenges in target detection.Variations in target size and occlusion often lead to misjudgments and missed detections.To address these issues, an enhanced vehicle and pedestrian detection model, YOLOv8nRLD, is proposed.It integrates several innovations to enhance target detection accuracy.Firstly, the introduction of the Receptive-Field Convolutional Block Attention Module enhances the model's ability to detect and emphasize salient features, facilitating more precise target localization and identification.Additionally, the Spatial Pyramid Pooling Fast module within the backbone feature extraction network is refined with the inclusion of the Large Separated Kernel Attention module.This augmentation significantly boosts the network's feature extraction capabilities.Furthermore, the adoption of a dynamic target detection head, termed Dynamic Head, incorporating attention mechanisms and diverse perception capabilities, enhances the model's feature expression capacity.Experimental validation on the BDD100K and Cityscapes datasets demonstrates notable performance enhancements, with mean Average Precision increasing by 4% and 2.5%, respectively.Ablation experiments confirm the effectiveness of individual modules, underscoring the method's efficacy and versatility in vehicle and pedestrian detection tasks.
Environmental vibration energy harvesting has received widespread attention recently, but existing research mainly focuses on cantilever beams.The fixing method of the cantilever beams limits its application range.A theoretical model and experimental results of a rectangular piezoelectric beam's modal frequencies and environmental vibration energy harvesting capacity are presented in this study.Accurate evaluation of piezoelectric beams' modal frequencies and energy harvesting capacity is extremely important to monitor and harvest energy from environmental vibrations.This paper establishes a model for the modal frequencies and response of a rectangular piezoelectric beam based on the Euler-Bernoulli beam theory and piezoelectric constitutive equation.In this paper, a fixed-size rectangular piezoelectric beam was selected for verification.The theoretical model was calculated using the modal superposition method.Then, the modal frequencies of piezoelectric beams were simulated using COMSOL, which is a multiphysics simulation software, and compared with theoretical values.Next, the modal frequencies of the piezoelectric beams and the vibration response of the theoretical results were verified through multiple sets of experiments.The experimental results show that the theoretical evaluation error of the modal frequencies of the piezoelectric beams is 1.23%, and the calculation average errors of the output voltage and power of the rectangular piezoelectric beams are 2.7% and 12.3%.The theoretical model effectively predicted the modal frequencies, output voltage, and power of the rectangular piezoelectric beams, demonstrating its potential for monitoring and harvesting environmental vibration energy.
The innovative energy-efficient vending machine for use in urban environment, called SVIEE-R, have been developed in the global context of reducing energy consumption and using alternative energies.In the design and prototype building phase of the SVIEE-R we analysed energy consumption for several models of the product delivery subsystem.In order to optimise the energy consumption for the product delivery subsystem we also considered the mechatronic delivery system with a spiral for packaged products.Building an energy efficient mechatronic delivery system allows to increase the lifetime of energy independent vending machines and concerning vending machines supplied from the public electricity grid to reduce greenhouse gas emissions.The use of modern design software allowed the analyse of the functioning of the mechatronic spiral systems from the design stage.The paper presents the research undertaken for the energy efficiency of the mechatronic spiral system using simulations of the operation validated through functional tests using a stand made by modern manufacturing technologies (laser cutting, 3D printing).The tests carried out were mainly aimed at evaluating the energy consumption of mechatronic spiral delivery systems.
In order to enhance the national research and development capability of large five-axis linkage machine tools, promote the improvement of performance and accuracy, promote industrialization, replace imports and meet the machining process requirements for large five-axis linkage machine tools in aviation and aerospace, this paper proposed a viaduct type five-axis gantry boring and milling machining centre.The centre's workbench is a floor standing platform, with the bed placed on both sides of the workbench.The two crossbeams are arranged back-to-back, and move longitudinally along the left and right guide rails (X-axis).The slide plate moves horizontally along the crossbeam guide rails (Y-axis), and the ram moves up and down along the slide plate (Zaxis).The double swing angle CNC universal milling head can achieve rotation around the Z-axis (Caxis) and X-axis (A-axis) to achieve five-axis simultaneous machining under the control of the CNC system.At the same time, the crossbeam of the machining centre has been structurally optimized to effectively reduce the weight of the moving parts, improve the dynamic performance of the machine tool and achieve a μ-level output of repeatable positioning accuracy for large strokes of the machine tool.
Petroleum pollution is an urgent and serious problem that has a negative impact on environmental safety and the state of the environment.Petroleum products that enter water resources cause a number of negative consequences, including water and soil pollution, reduced quality of natural ecosystems, as well as threats to biodiversity and human health.The purpose of this study is to assess the effectiveness of methods for treating surface wastewater of a machinebuilding enterprise from poll ution by petroleum products.In the course of the work, the results of cleaning the surface wastewater of the machine-building enterprise from pollution by petroleum products, samples of which were taken from the rainwater intake well at different depths -30, 60 and 80 cm.A purification scheme has been developed and optimized, which includes the introduction of Al2(SO4)3 coagulant and A-19 flocculant into wastewater.Purification efficiency is achieved at about 95% at optimal reagent doses of 60-80 mg/L coagulant and 2-2.5 mg/L flocculant.The advantage of the conducted studies is the possibility of using the obtained data and methods for the analysis of wastewater with a similar composition of contaminants.It has been experimentally established that the simultaneous administration of reagents or the use of only one of them has lower efficiency and leads to insufficient purification of water from petroleum products.Neutralization of ion resistance contributes to the formation of coagulation structures, and to increase them it is recommended to use a flocculant to form and increase the size of aggregates.The results of the studies confirmed the prospect of using flotation to further separate the emerging petroleum flocculi, which allows to reduce the amount of reagents used and improve the efficiency of water treatment.The obtained data are important for practical application in the field of wastewater treatment from petroleum products at machine-building enterprises, contributing to the improvement of the quality of water resources and compliance with environmental safety requirements.
This article presents researches conducted on samples obtained by micro alloying aluminum alloys with germanium oxide.Experiments were carried out on aluminum-magnesium, aluminum-copper and aluminum-manganese aluminum alloys, and the hardness and microstructure of the samples obtained by casting were studied.The samples were melted in the open air in a resistance furnace and poured into sand-clay molds.Germanium oxide was added to the charge in a rolled state using a special aluminum coating.Depending on the weight of the charge and the oxide's germanium concentration, between 0.1 and 0.3 percent of germanium oxide was added to aluminum alloys.An optical metallographic microscope was used for microscopic analysis of cast samples.Studies have shown that the germanium addition significantly destroys the microstructure of an aluminum alloy with intermetallic granules.Moreover, the hardness of the researched samples was studied.The authors outlined their recommendations and conclusions at the end of the article.
The bearing group is a key load-bearing structure of positive displacement motor (PDM), which experiences significant alternating heavy loads during the drilling process and causes failure accidents.In order to study the failure mechanism of the bearing group, the bearing group of the 165mm positive displacement motor was taken as the research object.Based on the structural characteristics of the drive shaft assembly and the point contact theory of the thrust ball bearing, the load of the thrust bearing was analyzed and calculated.A finite element model was established for the nonlinear contact problem between the steel ball, stator, and rotor, and numerical analysis was conducted for ball bearings with different degrees of wear.The research results indicate that: 1) it is easy to cause fatigue fracture of the inner and outer rings when the series bearing operates for a long time and under the special working conditions.In addition, the inner ring of the string bearing has problems such as unqualified surface roughness and local hardness, which exacerbates the damage of the string bearing.2) As the wear increases, the contact area between the bearing stator, rotor, and ball gradually decreases, and the stress concentration at the contact area between the steel ball and the stator and rotor intensifies, resulting in a significant increase in contact stress.3) The maximum Mises stress, contact force, and contact stress that bearings are subjected to are greatly affected by ball wear.Once the ball wears, the stress concentration phenomenon will lead to a rapid increase in the bearing capacity of the shaft, which will intensify with the increase of drilling pressure.4) Under the same working conditions, the maximum stress of the ball after wear of 1.5mm increased by 7.3 times compared to that without wear, resulting in bearing failure.The research methods and results of this article provide theoretical guidance for reducing the failure accidents of positive displacement motor bearing groups.
Cellulose and reduced graphene oxide (rGO) composites have garnered significant attention for their potential in transistor applications, combining environmental sustainability with advanced electrical functionalities.This comprehensive review delves into the recent advancements in the synthesis, characterization, and application of cellulose/rGO composites, particularly in the realm of transistors.We explore various synthesis methodologies such as in-situ reduction, chemical grafting, and physical mixing, examining their effects on the composites' structural, chemical, and morphological properties.The review highlights the deployment of these composites in diverse transistor types including field-effect transistors (FETs), organic field-effect transistors (OFETs), and biosensors, emphasizing their design, functionality, and performance enhancements.Furthermore, we discuss strategies for material optimization such as tuning composite ratios, functionalization, and the integration of additional materials to boost electrical conductivity, charge carrier mobility, and sensitivity.The review also addresses the challenges of scalability, reproducibility, and long-term stability of cellulose/rGO composites, proposing future research directions for novel composite formulations, device architectures, and broader applications in flexible and wearable electronics.This analysis not only underscores the unique properties of cellulose/rGO composites but also their transformative potential in developing sustainable, high-performance electronic devices.
In the realm of ankle rehabilitation, a novel 2-UPS/RRR parallel ankle rehabilitation robot (ARR) was introduced, taking into consideration the strengths and weaknesses of existing ankle rehabilitation robot models.The design process involved creating a 3D model of the mechanism using Solidworks software, and developing a movable platform with an adjustable rotation center to accommodate varying ankle rotation centers among patients.The degrees of freedom (DOF) were determined utilizing the Kutzbach-Gru bler formula.Geometric relationships were employed to derive kinematic inverse solution equations for the mechanism, which were subsequently validated through simulation and analysis using Matlab and Adams software.Displacement and velocity change profiles of the mechanism were generated through Adams software, the curve trend clearly indicates that the ankle rehabilitation mechanism exhibits smooth movement and demonstrates excellent kinematic performance.Furthermore, the impact of rehabilitation training on muscle strength and muscle activity in ankle-related muscles was assessed through biomechanical simulation software, specifically the AnyBody Modeling System, revealing effective training and rehabilitation outcomes for the pertinent muscles surrounding the ankle joint.Overall, the findings of this study suggest that the developed ankle rehabilitation robot is capable of fulfilling ankle rehabilitation duties and holds substantial practical significance.
Aluminium oxide (Al2O3) thin film has significant applications in optoelectronic devices due to its excellent photoelectric properties.To investigate the effect of deposition temperature on the photoelectric properties of ALD-Al2O3 films, samples with different deposition temperatures were prepared on silicon and K9 glass substrates using atomic layer deposition (ALD).The crystal structure and surface morphology of the samples were characterized using X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively.The thickness, refractive index and extinction coefficient of the films were measured by spectroscopic ellipsometry (SE) in the wavelength range of 275~800 nm and fitted by Tauc-Lorentz (T-L) model.The fitted thickness and bandwidth results were verified using scanning electron microscopy (SEM) and ultraviolet-visible (UV-VIS) absorption spectroscopy.The results show that the surface of the ALD-Al2O3 film is smooth and dense at low temperatures.The surface roughness was approximately 0.3 nm, which was measured with AFM, and this value differs from the SE fitting results due to the local minimum obtained by SE, while the AFM test is a global minimum.The growth rate of 100cycles sample is about 0.1 nm/cycle, and the band gap is about 3.30 eV by SE.The 500cycles sample thickness is 54.9 nm measured by SEM, and the band gap is about 3.25 eV by UV-VIS extrapolation.The accuracy of the fitted model is verified by the correspondence between the fitted and test results.
In this manuscript, the impact of a permanent magnetic field on the intensity of external lubricant/gaseous metal cutting environments in the turning process is studied.Tool life and wear resistance of solid High-Speed Steel (HSS) metal cutting tool was researched in diverse cutting modes and environments in turning steel 40X [analog: AISI 5135] and steel 25 [analog: AISI 1025] to study the effect of permanent magnetic field on the ferromagnetic tool.Experiments were conducted creating machine oil, oxygen, and argon conditions as an exterior machining environment in the process.The ferromagnetic HSS cutting tool is magnetically treated and used in diverse external machining conditions to analyze the intensity of affecting the lubricant/gaseous environment in the metal machining process.Furthermore, the influence of cutting speed and feed on the efficiency of magnetic field impact in lubricating and gaseous environment in the machining process is also researched.According to the experimental study, it is found that tool life and wear resistance of ferromagnetic HSS cutting tool is increased after the tool is magnetically treated with 10,000 ÷ 20,000 Oe of magnetic field strength in machining.However, the magnetic field effect on the HSS cutting tool showed subsidence while the cutting speed was increased in all external environments.Also, it is found that supplying oxygen and argon gases in metal cutting areas has a noticeably positive effect on tool wear and life, especially, since the influence of the gaseous environments has intensified results while the tool is used after magnetic treatment.
In the article, the general properties of copper nanoparticles, their requirements, recommendations for use, and methods of production are presented.In recent times, since copper nanoparticles are increasingly being used in electronics, as catalysts, as coatings on metal surfaces, and to aid in the medical field, the demand for copper nanoparticles may increase dramatically soon.After analyzing the existing technologies, experiments were carried out using the method of chemical precipitation with the help of iron as an environmentally and economically effective technology.In the experiments, surfactants used for protection against oxidation, experimental temperature, concentration and optimal parameters were determined. .The results of the analysis of several XRF spectra, SEM scanning electron microscope, IR-Fourier spectrometer, UV diffusion reflection spectroscopy of raw materials and obtained samples are presented.Based on the experiment, the conditions for obtaining the results of 98.3% pure copper particles with a fineness of 170 nm are explained.
Various techniques have been proposed to manufacture prosthetic sockets, which are essential in improving the quality of life among amputees and individuals with special needs.However, the fabrication of prosthetics using the available approaches is uneconomical due to the type of materials utilized during the production, as well as the direct methods that use expensive materials to produce prosthetic parts.Considering this, it is crucial to enhance the direct methods by exploiting cost-effective materials to produce prosthetic parts with desirable behaviors.Therefore, this study aimed to compare the fatigue performance of below-knee (BK) prosthetic sockets manufactured using three different techniques: laminate, direct, and novel.The three sockets specimens were first manufactured.Specimen A was made via the direct method using 4 layers of carbon fiber as the reinforcement and AX140401 as the matrix.Specimen B was also fabricated via the lamination method using 4 layers of carbon fiber as the reinforcement and lamination resin + hardener acrylic as the matrix.Finally, specimen C was made via the direct novel method using 4 layers of carbon as the reinforcement, and the matrix was composed of 20% polyurethane resin (part A: resin, part B: hardener) + 80% acrylic.Subsequently, the pressure distribution at the contact point between the socket and the residual limb was analyzed using the F-SOCKET device.Furthermore, the numerical analysis included the distribution of the stress and the highest internal pressure, the number of cycles ascertained through the utilization of the SOLIDWORKS software.Based on the results, the S-N curves for each specimen show that all three specimens behaved similarly.Using the F-socket, the pressure during the patient's walking cycle reached its highest point at 190 kPa.In addition, applying ground reaction force from the bottom of the direct, lamination, and novel BK prosthetic sockets demonstrated the pressure distribution of the part that reacts to the loading condition.The SOLIDWORKS program revealed from the pressure distribution of the three sockets measured a maximum internal pressure of 191 kPa, 193 kPa, and 191 kPa sequentially, which was close to the pressure within the F-socket.Besides, the number of cycles for the direct, lamination, and novel BK prosthetic sockets was 1,332,345, 1,202,345, and 1,203,567 cycles.In summary, all three specimens fabricated via the direct, lamination, and novel methods achieved similar fatigue performance of BK prosthetic sockets.So, the novel BK prosthetic socket wad designed in which fabricated using a new matrix material was considered acceptable, similar to specimens A and B.
Today, there is a trend in world tractor manufacturing to use continuously variable transmissions instead of mechanical stepped transmissions.The most popular continuously variable transmissions are variator, hydraulic-mechanical and electromechanical.For wheeled tractors, of course, the most common transmission is the dual-flow hydraulic-mechanical continuously variable transmission.Today, there are such models of tractors with HMCVT on the world market as John Deere, Case IH, John Deere, Fendt, Massey Ferguson.Therefore, the objective of this paper is to analyse the response of dual-flow transmissions used on wheeled tractors in terms of efficiency and productivity, taking into account the circulating modes of operation.The implementation of the outlined objective is done through the use of basic mathematical equations, supported by the experimental identification of hydromechanical losses in the hydraulic branch of the transmission.When solving the set goal, the configuration of schematic solutions of the HMCVT structure with the placement of the planetary mechanism at the output of the dual-flow system was used.The result is a scientifically based analysis of the performance indicators of HMCVT according to efficiency and productivity criteria with different configurations of the schematic structure of the transmission.The practical significance of the work is to provide recommendations for changing the efficiency and productivity of the two-flow HMCVT by varying the circuit structure.A scientific novelty is the establishment of a relationship between the design parameters of dual-flow transmissions (the energy effect of the power variation in the mechanical branch) and their performance and efficiency criteria for different circuit configurations of the output planetary mechanism.
This detailed paper explores the complex dynamics of Digital Manufacturing in Industry 4.0, with the explicit aim of addressing and remedying significant gaps identified in academic literature.The paper provides extensive insight into how technological innovations, including additive manufacturing, the Industrial Internet of Things (IIoT) and Big Data analytics, are transforming industrial infrastructure and operations.By critically evaluating existing studies and current trends, the paper aims to elucidate not only the impact of emerging technologies, but also to reveal how they can be effectively integrated to increase efficiency and innovation capacity across various industrial sectors.The methodology adopted includes a thorough literature review, comparative analysis of relevant case studies and exploitation of current data, all with a view to developing pragmatic and actionable recommendations.Emphasis is placed on identifying and analyzing the key challenges that accompany the adoption of digital technologies, such as the substantial up-front investment required and the difficulties in preparing the workforce for the new technological requirements.The paper also explores how these challenges can be turned into opportunities to improve the industry's flexibility and adaptability to rapid market changes.The results highlight the significant benefits of implementing Digital Manufacturing, including process optimization, defect reduction, production customization and improved operational sustainability.The conclusions drawn emphasize the critical role of digital innovations in shaping the industrial future and recommend close collaboration between the public and private sectors to facilitate the widespread adoption of these technologies.Finally, the paper suggests that through continued investment in technology development and the implementation of well-designed integration strategies, Digital Manufacturing can lead to profound and sustainable transformations that stimulate economic growth and contribute to positive societal change.
Modelica is a powerful modelling language for modelling and simulation of Multiphysics Engineering Systems behaviour.This work explores a model to be implemented in the control design of a 6-axis industrial manipulator whose structure approaches the robotic arm ABB IRB 140, through inverse kinematics calculation.The significance of an inverse kinematics model is to bring accuracy to the reference inputs into a closed-loop control system involved in an industrial setting.Inverse kinematics can complement the path planner or trajectory generator function in object-oriented Modelica language, optimizing the study of an industrial robot physical process such a Pick&Place system.Finally, obtained results are extrapolated for similar cases and applications.
